Hi, Suggestions inlined below.
[email protected] writes: > ---------- Ursprüngliche Nachricht ---------- > Von: Michael Dittmer > An: "[email protected]" > <[email protected]> > Datum: 23.08.2020 12:00 > Betreff: book scanner recognized as v4l device > > I bought a book scanner > > JOURIST BT16 > > from a german dealer > > looks like: > http://www.scanner.expert/de/images/products/buchscanner/description/5_JOURIST_Buchscanner_BS16_Standalone.jpg > > > It takes photos from the pages with a camera like a CZUR book > scanner. My bookscanner camera also can be opened by > > guvcview > > It has maximum resolution of > > 4608x3456 > > pixels for A3 scan (resolution can be selected by gucview and is shown > later when starting xsane). > > When I plug it onto a usb port, several devices are recognized (dmesg > output) > > [...] > > All book scanner manufacturers seem to deliver only twain drivers. So > I tried to handle the scanner as an generic v4l device > > My linux mint 19.3 (based on Ubuntu 18.04) distribution has a sane > backend package (1.0.27) without compiled v4l backend. > After compiling current 1.0.30 sources with v4l-dev libraries I > obtained the v4l backend > > scanimage --list-devices > device `v4l:/dev/video3' is a Noname JY-VP216: JY-VP216 virtual device > > but xsane and scanimage are not able to perform scan ("illegal argument") Check the supported settings and allowed values with scanimage -d v4l:/dev/video3 --help --all-options > SANE_DEBUG_SANEI_USB=4 scanimage -v -d v4l:/dev/video3 --format tiff > > output.tif > scanimage: ignored request to set inactive option br-x > scanimage: ignored request to set inactive option br-y > scanimage: sane_start: Invalid argument Try SANE_DEBUG_V4L=128 scanimage -v -d v4l*/dev/video3 and see if that sheds any light upon your issue. > Another program > > simple scan > > from Ubuntu distribution is able to scan into pdf with 1600x1200 pixel > but not with maximum resolution. > > It seems for me that the v4l backend has to support higher > resolutions, like 4608x3456 e.g. Hope this helps, -- Olaf Meeuwissen, LPIC-2 FSF Associate Member since 2004-01-27 GnuPG key: F84A2DD9/B3C0 2F47 EA19 64F4 9F13 F43E B8A4 A88A F84A 2DD9 Support Free Software https://my.fsf.org/donate Join the Free Software Foundation https://my.fsf.org/join
